Rates of Marijuana Use in Cancer Patients on the Rise in U.S.

People with cancer also more likely to use prescription opioids than those without

MONDAY, April 22, 2019 (HealthDay News) -- Many people with cancer use marijuana, and the rates of use in the United States have increased over time, according to a study published online April 22 in Cancer.

After analyzing data from the U.S. National Health and Nutrition Examination Survey between 2005 and 2014, Kathryn R. Tringale, M.D., from the University of California San Diego in La Jolla, and colleagues matched 826 people with cancer to 1,652 controls without cancer.

Among survey respondents who had cancer, the researchers found that 40.3 percent had used marijuana within the previous year compared with 38 percent of respondents without cancer. People with cancer were also more likely to use prescription opioids than their demographically equivalent counterparts without cancer (13.9 versus 6.4 percent). When looking at rates of marijuana and opioid use in 19,604 survey respondents with and without cancer over 10 years, the authors found significantly increased use of marijuana over time -- likely reflecting increased availability due to legislative changes -- but they found stable rates of opioid use. A diagnosis of cancer did not significantly affect the odds of substance use over time from 2005 to 2014.

"Medical marijuana legalization has previously been associated with a reduction in hospitalizations related to opioid dependence or abuse, suggesting that if patients are in fact substituting marijuana for opioids, this may introduce an opportunity for reducing opioid-related morbidity and mortality," a coauthor said in a statement. "Of course, it will also be important to identify risks and adverse effects of marijuana, which has not previously been studied on large randomized clinical trials, given its scheduling as a class 1 controlled substance."